Patents by Inventor Tadashi Iizuka
Tadashi Iizuka has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
-
Patent number: 7128528Abstract: The object of the present invention is to provide: high-reliability and long-life CO2 refrigerant compressor-use bearings that uses bearing materials high in wear resistance and in baking resistance, and; such a compressor, air conditioner, refrigerator, and hot-water supply machine that each employ these bearings.Type: GrantFiled: April 22, 2003Date of Patent: October 31, 2006Assignees: Hitachi, Ltd., Toyo Tanso Co., Ltd.Inventors: Hiroshi Takayasu, Noboru Baba, Shouichi Nakashima, Tadashi Iizuka, Toshiaki Yamanaka, Hiroaki Ogura, Toshiomi Fukuda, Shinichi Ozaki
-
Bearings for C02 refrigerant compressor use, compressor using the same, and applications of the same
Publication number: 20030231815Abstract: The object of the present invention is to provide: high-reliability and long-life CO2 refrigerant compressor-use bearings that uses bearing materials high in wear resistance and in baking resistance, and; such a compressor, air conditioner, refrigerator, and hot-water supply machine that each employ these bearings.Type: ApplicationFiled: April 22, 2003Publication date: December 18, 2003Inventors: Hiroshi Takayasu, Noboru Baba, Shouichi Nakashima, Tadashi Iizuka, Toshiaki Yamanaka, Hiroaki Ogura, Toshiomi Fukuda, Shinichi Ozaki -
Patent number: 6258293Abstract: A refrigerating apparatus comprising a refrigeration cycle comprising at least a compressor, a condenser, a dryer, an expansion mechanism and an evaporator, a refrigerant composed mainly of a fluorocarbon type refrigerant containing no chlorine and having a critical temperature of 40° C. or higher, and a refrigerating machine oil comprising as base oil an ester oil of one or more fatty acids which contains at least two ester linkages in the molecule and has a viscosity at 40° C. of 2 to 70 cSt and a viscosity at 100° C. of 1 to 9 cSt.Type: GrantFiled: December 2, 1999Date of Patent: July 10, 2001Assignee: Hitachi, Ltd.Inventors: Tadashi Iizuka, Reishi Naka, Katsumi Fukuda, Makoto Tanaka, Yoshiharu Homma, Hiroaki Hata, Hirokatsu Kousokabe, Koji Nariyoshi, Hiroshi Iwata
-
Patent number: 6176094Abstract: The present invention relates to a refrigerating machine oil composition, which is composed of a base oil as a main component containing a single component of a compound or a mixture of compounds selected from the group consisting of cyclic carbonates and aliphatic carbonate derivatives. For example, the refrigerating machine oil composition is characterized by that the single component of a compound or the mixture of compounds selected from the group consisting of cyclic carbonates and aliphatic carbonate derivatives are expressed by the following general chemical formulas for cyclic carbonates (1) and aliphatic carbonate derivatives (2): (R1, R2 in the formula (1) respectively and independently express a hydrogen atom or a fluorine atom or an alkyl having a carbon number of 1 to 4, or a perfluoroalkyl having a carbon number of 1 to 3. Therein, R1 and R2 may be the same or different from each other.Type: GrantFiled: September 8, 1998Date of Patent: January 23, 2001Assignee: Hitachi, Ltd.Inventors: Ryou Ohta, Yutaka Ito, Kenichi Kawashima, Juichi Arai, Tadashi Iizuka
-
Patent number: 6029459Abstract: A refrigerating apparatus comprising a refrigeration cycle comprising at least a compressor, a condenser, a dryer, an expansion mechanism and an evaporator, a refrigerant composed mainly of a fluorocarbon type refrigerant containing no chlorine and having a critical temperature of 40.degree. C. or higher, and a refrigerating machine oil comprising as base oil an ester oil of one or more fatty acids which contains at least two ester linkages ##STR1## in the molecule and has a viscosity at 40.degree. C. of 2 to 70 cSt and a viscosity at 100.degree. C. of 1 to 9 cSt.Type: GrantFiled: April 22, 1998Date of Patent: February 29, 2000Assignee: Hitachi, Ltd.Inventors: Tadashi Iizuka, Reishi Naka, Katsumi Fukuda, Makoto Tanaka, Yoshiharu Homma, Hiroaki Hata, Hirokatsu Kousokabe, Koji Nariyoshi, Hiroshi Iwata
-
Patent number: 5964581Abstract: A refrigerant compressor using a refrigerant composed mainly of a fluorocarbon and/or hydrofluorocarbon type refrigerant containing no chlorine and having a critical temperature of 40.degree. C. or higher, and a refrigerating machine oil comprising as base oil an ester oil of one or more fatty acids which contains at least two ester linkages ##STR1## in the molecule and has a viscosity at 40.degree. C. of 2 to 70 cSt and a viscosity at 100.degree. C. of 1 to 9 cSt. The winding wire of the stator of the compressor has a core wire having an enamel coating having a glass transition temperature of 120.degree. C. or higher.Type: GrantFiled: March 4, 1996Date of Patent: October 12, 1999Assignee: Hitachi, Ltd.Inventors: Tadashi Iizuka, Reishi Naka, Katsumi Fukuda, Makoto Tanaka, Yoshiharu Homma, Hiroaki Hata, Hirokatsu Kousokabe, Koji Nariyoshi, Hiroshi Iwata
-
Patent number: 5711165Abstract: A regrigerating apparatus comprising a refrigeration cycle comprising at least a compressor, a condenser, a dryer, an expansion mechanism and an evaporator, a refrigerant composed mainly of a fluorocarbon type refrigerant containing no chlorine and having a critical temperature of 40.degree. C. or higher, and a refrigerating machine oil comprising as base oil an ester oil of one or more fatty acids which contains at least two ester linkages ##STR1## in the molecule and has a viscosity at 40.degree. C. of 2 to 70 cSt and a viscosity at 100.degree. C. of 1 to 9 cSt.Type: GrantFiled: September 20, 1994Date of Patent: January 27, 1998Assignee: Hitachi, Ltd.Inventors: Tadashi Iizuka, Reishi Naka, Katsumi Fukuda, Makoto Tanaka, Yoshiharu Homma, Hiroaki Hata, Hirokatsu Kousokabe, Koji Nariyoshi, Hiroshi Iwata
-
Patent number: 5591023Abstract: A compressor comprising a roller made of a cast iron which has a hardness of HRC 50 or more after heat treatment, and contains not less than 5 area % of graphite, and not less than 2 area % of crystallized eutectic structure including iron phosphide, and either a vane made of a material which has a hardness of HRC 70 or more after heat treatment and contains not less than 25 area % of undissolved carbides and nitride particles in total, the undissolved carbides including not less than 10 area % of MC type carbides, the nitride particles including at least one of TiN and NbN of not less than 5 area %, the undissolved carbides and the nitride particles having a mean grain size of not more than 5 .mu.m, or a vane made of a material including at least one of TiN and NbN particles of not less than 5 area %, the TiN and NbN particles having a mean grain size of not more than 5 .mu.m, the material essentially consisting of, by weight, 2.0 to 4.0 % of C, not more than 2.0 % of Si, not more than 1.5 % of Mn, 2.5 to 8.Type: GrantFiled: October 10, 1995Date of Patent: January 7, 1997Assignees: Hitachi Metals, Ltd., Hitachi, Ltd.Inventors: Hideki Nakamura, Keiji Yamasaki, Fujio Yamane, Toshiki Yoshida, Tadashi Iizuka, Akihiko Ishiyama
-
Patent number: 5553465Abstract: A lubricant composition comprising as a base oil one or more ester oils, alkylbenzene oils and mineral oils, and a glycidyl ether compound having at least two epoxy groups is miscible in hydrofluorocarbon and hydrochlorofluorocarbon refrigerants such as R134a, etc. as replacing refrigerants of R12 and provides a stable operation of refrigeration compressor for a long period of time without causing corrosion and wear of a sliding portion of the compressor.Type: GrantFiled: October 13, 1994Date of Patent: September 10, 1996Assignee: Hitachi, Ltd.Inventors: Katsumi Fukuda, Tadashi IIzuka, Reishi Naka, Hiroaki Hata, Masahiko Gommori, Yoshiharu Homma
-
Patent number: 5494423Abstract: A rotary compressor has a compression chamber defined by a rolling piston which is eccentrically rotated in a cylinder by a rotary shaft including an eccentric crank portion, and by a blade which slides in a groove formed in the cylinder and of which the tip contacts an outer-peripheral surface of the rolling piston.Type: GrantFiled: February 17, 1995Date of Patent: February 27, 1996Assignee: Hitachi, Ltd.Inventors: Akihiko Ishiyama, Ken'ichi Kawashima, Hirokatsu Kohsokabe, Shoichi Nakashima, Hideki Yazawa, Hiroaki Hata, Tadashi Iizuka, Kazuo Sekigami, Koichi Sato
-
Patent number: 5478220Abstract: The present invention provides an Al--Si based sintered alloy of high strength and high ductility, a method for production thereof and use thereof. The alloy comprises 1-45% of Si, 0.1-20% of an element of Group IIIa, 0.01-5% of at least one element of Groups IVa and Va, the balance of substantially Al. This alloy can further contain at least one of 0.01-5% of Cu, 0.01-5% of Mg, 2.0% or less of Fe, 1.5% or less of Mn and 1.5% or less of Co and the oxygen content is reduced to 0.15% or less by sintering under vacuum. The present invention is applied to automobile parts such as a piston and scroll compressors. The alloy has a tensile strength of about 40 kg/mm.sup.2 or higher and an elongation of 1.5% or more at 150.degree. C.Type: GrantFiled: September 23, 1994Date of Patent: December 26, 1995Assignees: Hitachi, Ltd., Hitachi Powdered Metals Co., Ltd.Inventors: Yasuo Kamitsuma, Yusaku Nakagawa, Mitsuo Chigasaki, Tadashi Iizuka, Kooichi Inaba, Keiichi Nakamura, Masaki Minabe, Tsuyoshi Kagaya
-
Patent number: 5445753Abstract: A lubricant composition comprising as a base oil one or more ester oils, alkylbenzene oils and mineral oils, and a glycidyl ether compound having at least two epoxy groups is miscible in hydrofluorocarbon and hydrochlorofluorocarbon refrigerants such as R134a, etc. as replacing refrigerants of R12 and provides a stable operation of refrigeration compressor for a long period of time without causing corrosion and wear of a sliding portion of the compressor.Type: GrantFiled: March 17, 1993Date of Patent: August 29, 1995Assignee: Hitachi, Ltd.Inventors: Katsumi Fukuda, Tadashi Iizuka, Reishi Naka, Hiroaki Hata, Masahiko Gommori, Yoshiharu Homma
-
Patent number: 5423664Abstract: A roller of a rotary type compressor is made of an iron base alloy essentially consisting of 2.0 to 3.9% carbon, 2.0 to 3.0% Si, 0.3 to 1.0% Mn, up to 0.10% S, more than zero and not more than 0.50% V, 0.3 to 1.0% P, 0.01 to 0.5% Sb, and balance of Fe and incidental impurities. Preferably, the iron base alloy further includes 0.001 to 0.5% B. This roller is suitable when hydrofluorocarbon is used as a refrigerant.Type: GrantFiled: July 15, 1994Date of Patent: June 13, 1995Assignee: Hitachi, Ltd.Inventors: Tadashi Iizuka, Kazushi Fukuda, Akihiko Ishiyama, Hideki Yazawa, Shoichi Nakashima, Hideki Nakamura
-
Patent number: 5417872Abstract: A lubricant composition comprising as a base oil one or more ester oils, alkylbenzene oils and mineral oils, and a glycidyl ether compound having at least two epoxy groups is miscible in hydrofluorocarbon and hydrochlorofluorocarbon refrigerants such as R134a, etc. as replacing refrigerants of R12 and provides a stable operation of refrigeration compressor for a long period of time without causing corrosion and wear of a sliding portion of the compressor.Type: GrantFiled: March 17, 1993Date of Patent: May 23, 1995Assignee: Hitachi, Ltd.Inventors: Katsumi Fukuda, Tadashi Iizuka, Reishi Naka, Hiroaki Hata, Masahiko Gommori, Yoshiharu Homma
-
Patent number: 5387272Abstract: The present invention provides an Al-Si based sintered alloy of high strength and high ductility, a method for production thereof and use thereof. The alloy comprises 1-45% of Si, 0.1-20% of an element of Group IIIa, 0.01-5% of at least one element of Groups IVa and Va, the balance of substantially Al. This alloy can further contain at least one of 0.01-5% of Cu, 0.01-5% of Mg, 2.0% or less of Fe, 1.5% or less of Mn and 1.5% or less of Co and the oxygen content is reduced to 0.15% or less by sintering under vacuum. The present invention is applied to automobile parts such as a piston and scroll compressors. The alloy has a tensile strength of about 40 kg/mm.sup.2 or higher and an elongation of 1.5% or more at 150.degree. C.Type: GrantFiled: April 8, 1992Date of Patent: February 7, 1995Assignees: Hitachi, Ltd., Hitachi Powdered Metals Company, LimitedInventors: Yasuo Kamitsuma, Yusaku Nakagawa, Mitsuo Chigasaki, Tadashi Iizuka, Kooichi Inaba, Keiichi Nakamura, Masaki Minabe, Tsuyoshi Kagaya
-
Patent number: 5364248Abstract: The object of the present invention is to provide sliding members having preferable lubrication and seizure resistance. Sliding members comprising a columnar texture which is composed from at least one of metal nitrides, metal oxides, metal carbides, and metals on a base member, wherein the columnar texture is composed of assemblies of fine columnar asperities, with intervals formed between the columnar asperities being connected to each other so as to form a net work, and with gaseous, liquid, or solid lubricants being maintained in the intervals. The mutually connected intervals in the columnar texture are superior in filling and holding of lubricants, and the above described superiorities improve lubrication and seizure resistance and extend sliding life.Type: GrantFiled: March 23, 1993Date of Patent: November 15, 1994Assignee: Hitachi, Ltd.Inventors: Shoichi Nakashima, Yukiko Fukaya, Katsuhiro Komuro, Tadashi Iizuka
-
Patent number: 5346667Abstract: A method of manufacturing sintered Al-Si series alloy parts having complex configurations such as scroll shaped parts wherein Al-Si series alloy powder solidified via rapid cooling prepared by adding effective components such as Si, Cu, Mg, Fe, Mn, Zr and Ce to Al is compression molded, the molded body is sintered by heating via an electrical current conduction in a form of a plasma discharge and then the sintered body is worked by pressing, thereby the parts having complex configurations of light weight, high mechanical strength and toughness is manufactured with a simple installation and reduced processing manhours, and with a high efficiency and at a low cost.Type: GrantFiled: September 29, 1992Date of Patent: September 13, 1994Assignees: Hitachi, Ltd., Hitachi Powdered Metals Co., Ltd.Inventors: Yasuo Kamitsuma, Yusaku Nakagawa, Yoshihiro Kobayashi, Shoichi Nakashima, Tadashi Iizuka, Keiichi Nakamura, Hideo Shikata
-
Patent number: 5090882Abstract: A rotary compressor has a plate-like hollow vane disposed in sliding contact with a rotary piston. The vane has an internal cavity formed by a plurality of bores each having a substantially rectangular cross-section. The corners of each bore are each formed by a curved concave surface of a radius of curvature which is greater than the thicknesses of the outer walls of the vane. The major side surfaces of the vane are in slidable contact with opposing walls of a vane slot and have surface layers each formed of an oxide film consisting mainly of tri-iron tetraoxide (Fe.sub.3 O.sub.4). The film is finished by smoothing processing, thus attaining a smaller friction between the vane major side surfaces and the vane slot walls and suppressing local wear of the vane slot walls.Type: GrantFiled: July 26, 1990Date of Patent: February 25, 1992Assignee: Hitachi, Ltd.Inventors: Yukio Serizawa, Koichi Sekiguchi, Yasuhiro Oshima, Tadashi Iizuka
-
Patent number: 5087181Abstract: A sliding structure such as a compressor and etc. comprising a member made of an iron base material and another member having a porous ceramic layer slidably contacted with the iron base member, wherein the surface portion of the iron base member has both a porous oxide film containing tri-iron tetroxide as a main constituent, and an oxynitride layer formed under the oxide film.Type: GrantFiled: March 6, 1990Date of Patent: February 11, 1992Assignee: Hitachi, Ltd.Inventors: Yasuo Kamitsuma, Isao Ishi, Yusaku Nakagawa, Noriyuki Ohnaka, Tadashi Iizuka, Kazushi Fukuda
-
Patent number: 4944663Abstract: A sliding member of an iron-based non-porous material, such as vane, of a rotary compressor has a sliding surface processed by a surface treatment in which the surface is subjected to oxidizing and nitriding to form an oxidized and nitrided layer thereon. The surface is then subjected to a steam-treatment in which water is caused to react with components of the oxidized and nitrided layer to form a layer of oxidized iron of a porous network structure disposed outwardly of the oxidized and nitrided layer. The oxidized iron layer is composed mainly of tri-iron tetroxide and softer than the oxidized and nitrided layer.Type: GrantFiled: April 19, 1989Date of Patent: July 31, 1990Assignee: Hitachi, Ltd.Inventors: Tadashi Iizuka, Kazushi Fukuda, Shin Ishihara, Yasuo Kamitsuma, Yusaku Nakagawa